Genes with no CpG islands... - (Jul/15/2005 )

Hi

I am very new to this forum, but actively reading forums question and answers. I have found that the answers were very relevant and helps one to trouble shoot correctly. I have one question to the members: I have some genes whose promoter regions do not contain any CpG islands but few CpG sites are located upstream of the exon1. In my experiments these genes are differentially expressed when compared to controls. And these genes are involved in metabolism. Is it worthwhile to look for methylation and acetylation status of these genes. Waiting for your reply.

Thanks
mpg.

If a gene doesn't have a CpG island at its promoter region, I would not bother to map its methylation. But histone modification is a different story and may be independent of DNA methylation and CpG island.

I agree with Pcrman,

look at histone modifcations such as H3K9 methylation on the inactive allele and H3 acetylation for active alleles

Nick

Thanks for the information. Does DNA methylation and histone acetylation go in concert.

directly opposite, you shouldn't see DNA methylation within hyperacetylated histones. and you shouldn't see hyperacetylated histones where there is heavy DNA methylation.

Nick

There are papers reporting clear associations between non CpG island methyaltion status and gene expression status. Whether the methylation status of these sites is a marker of the transcription activity of the DNA or is acutally invovled in the regulation of transcription, is a question I am hoping to answer... watch this space.